This invention is in the field of casting/molding methods. This invention relates generally to methods of making molded or cast microstructured objects.
Casting and molding methods have long been utilized for producing and replicating objects. In general, the negative of an object is produced in a casting or molding process; that is, recessed features are replicated as raised features and vice versa. As such, at least two steps are generally required for replication of an object or features via casting or molding. First, a mold or form of an object is created around or on the master object, creating a negative of the master. For a casting method, the mold or form is filled with an end product material, creating a negative of the mold or form, which results in an end product generally resembling the master. In a molding method, the mold or form is stamped onto the end product material and the features of the master are replicated into the end product. Alternatively, the negative of the desired end product can be fabricated directly and used in a casting, molding or stamping process.
Only recently, however, have casting and molding methods been applied to microstructured objects. A limited number of U.S. patents and patent application Publications disclose cast or molded microstructured objects. For example, U.S. Patent Application Publication US 2006/0162896 discloses methods for forming microstructured metallic surfaces via single use wax molds. U.S. Pat. No. 5,735,985 discloses a method for high pressure compression molding of ceramic micro scale articles, for example a micro molded integrated ceramic light reflector. U.S. Pat. No. 7,237,337 discloses a heat dissipating apparatus having a microstructured capillary layer formed by injection molding or printing. U.S. Pat. No. 7,410,606 discloses casting methods for microstructured objects utilizing a mold fabricated from multiple thin layers stacked to form the desired micro mold.